666664417 has 8 divisors (see below), whose sum is σ = 670700160. Its totient is φ = 662637360.

The previous prime is 666664399. The next prime is 666664429. The reversal of 666664417 is 714466666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666664417 - 2¹⁹ = 666140129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666664477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212184 + ... + 215302.

It is an arithmetic number, because the mean of its divisors is an integer number (83837520).

Almost surely, 2^666664417 is an apocalyptic number.

It is an amenable number.

666664417 is a deficient number, since it is larger than the sum of its proper divisors (4035743).

666664417 is a wasteful number, since it uses less digits than its factorization.

666664417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4343.

The product of its digits is 870912, while the sum is 46.

The square root of 666664417 is about 25819.8454100717. The cubic root of 666664417 is about 873.5794821028.

The spelling of 666664417 in words is "six hundred sixty-six million, six hundred sixty-four thousand, four hundred seventeen".